There is a sheet processing apparatus which can execute both a decoloring processing and an image forming processing. In the sheet processing apparatus, it is considered that a cassette is used as not only a sheet discharge cassette for stacking the discharged sheet subjected to the decoloring processing, but also a sheet feed cassette for feeding the sheet to be subjected to the image forming processing.
In this case, it is required to equip with a pickup mechanism in the sheet processing apparatus to pick up sheets from the cassette. Further, in order to ensure the accuracy when performing the image forming processing on the sheet, it is required to equip with an alignment mechanism to align the sheets to be discharged to the cassette.
Thus, when the cassette is used as both the sheet discharge cassette and the sheet feed cassette in the sheet processing apparatus, there is a problem that the sheet processing apparatus becomes large-sized because it is required to equip with the alignment mechanism in addition to the pickup mechanism.